High School

Which of the following is the correct statement for the equation Δh = qp?

1) qp is path dependent and Δh is independent of path
2) qp is path independent and Δh is dependent on path
3) qp and Δh are both path dependent
4) qp and Δh are both path independent

Answer :

The correct statement is that qp is path dependent and \\(\\Delta h\\) is independent of path, indicating that while heat transferred at constant pressure varies with the process path, enthalpy change is a state function and remains constant for any path between two states.

The statement that is correct for the equation \\(\\Delta h = qp\\) is: qp is path dependent and \\(\\Delta h\\) is independent of path. This means that the heat transferred at constant pressure (qp) can vary depending on the specific pathway taken during a process, whereas the change in enthalpy (\\(\\Delta h\\)) is a state function and thus does not depend on the path taken between two states. In thermodynamics, state functions like \\(\\Delta h\\) only depend on the initial and final states, not on how the change occurs.

Path dependence or independence is crucial in thermodynamics, since it allows us to calculate changes in state functions (like enthalpy) without needing to know the specifics of the path taken. For example, whether heat is added slowly or quickly, or whether work is done in one stage or multiple stages, doesn't affect the calculation of \\(\\Delta h\\) for a process occurring at constant pressure.